Target tissue localization device

ABSTRACT

A target tissue localization device ( 28 ) has outer and inner members ( 30, 32 ) which are longitudinally movable relative to one another. An anchor ( 42 ) is secured to the outer and inner members and is movable from a radially-contracted configuration to a radially-expanded configuration. The anchor may be a tubular mesh anchor. The anchor may have a sufficiently large cross-sectional area when in the radially-expanded configuration to substantially eliminate inadvertent dislodgment of the anchor once radially-expanded. In use, the location of the target tissue ( 56 ) is determined and the distal end of the localization device is passed through the patient&#39;s skin ( 58 ) and to the target tissue to create a tissue track ( 60 ) between the patient&#39;s skin and the target tissue. The target tissue includes near and far sides ( 62, 64 ). The anchor element, located at the target tissue is expanded to an expanded configuration. The method the anchor element may be located on the far side of the target tissue. The localization device may be selected with an anchor which is palpable for relocation of the target tissue.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of U.S. patent applicationSer. No. 09/678,508 filed on Oct. 2, 2000, which application is acontinuation of U.S. patent application Ser. No. 09/376,678 filed onAug. 18, 1999, now U.S. Pat. No. 6,179,860, which patent claims thebenefit of the following Provisional Patent Applications: BiopsyLocalization Device, Application No. 60/097,126, filed Aug. 19, 1998;Biopsy and Tissue Localization Device, Application No. 60/106,733, filedNov. 2, 1998.

[0002] This application is related to: U.S. patent application Ser. No.09/336,360 filed Jun. 18, 1999 for Biopsy Localization Method andDevice; U.S. patent application Ser. No. 09/248,083 filed Feb. 9, 1999for Occlusion, Anchoring, Tensioning and Flow Direction Apparatus andMethods for Use.

BACKGROUND OF THE INVENTION

[0003] In the U.S. alone approximately one million women will havebreast biopsies because of irregular mammograms and palpableabnormalities. Biopsies can be done in a number of different ways fornon-palpable lesions, including surgical excisional biopsies andstereotactic and ultrasound guided needle breast biopsies. In the caseof image directed biopsy, the radiologist or other physician takes asmall sample of the irregular tissue for laboratory analysis. If thebiopsy proves to be malignant, additional surgery (typically alumpectomy or a mastectomy) is required. In the case of needle biopsies,the patient then returns to the radiologist a day or two later where thebiopsy site (the site of the lesion) is relocated by method calledneedle localization, a preoperative localization in preparation for thesurgery.

[0004] Locating the previously biopsied area after surgical excisiontype of biopsy is usually not a problem because of the deformity causedby the surgery. However, if the biopsy had been done with an imagedirected needle technique, as is common, help in relocating the biopsysite is needed. One procedure to permit the biopsy site to be relocatedby the radiologist during preoperative localization is to leave some ofthe suspicious calcifications; this has its drawbacks.

[0005] Another way to help the radiologist relocate the biopsy siteinvolves the use of a small metallic surgical clip, such as those madeby Biopsys. The metallic clip can be deployed through the biopsy needle,and is left at the biopsy site at the time of the original biopsy. Withthe metallic clip as a guide, the radiologist typically inserts a barbedor hooked wire, such as the Hawkins, Kopans, Homer, Sadowski, and otherneedles, back into the patient's breast and positions the tip of thewire at the biopsy site using mammography to document the placement. Thepatient is then taken to the operating room with the needle apparatussticking out of the patient's breast. While the clip provides a goodindication of the biopsy site to the radiologist during preoperativelocalization, the clip remains permanently within the 80% of patientswith benign diagnoses. Also, because the clip is necessarily attached toa single position at the periphery of the biopsy site, rather than thecenter of the biopsy site, its location may provide a misleadingindication of the location of diseased tissue during any subsequentmedical intervention. The clip is also relatively expensive. Inaddition, the soft nature of breast tissue permits the tip of the barbedor hooked needle to be relatively easily dislodged from the biopsy site.The surgeon typically pulls on the needle to help locate the area to beremoved. This pulling motion during the excision may be responsible morethan any other single factor for the movement of the needle.Additionally, these devices are not easily felt by external palpationand the tip is difficult to locate without dissection into the tissues;this prevents a surgical approach which may be more cosmeticallyadvantageous and surgically appropriate than dissecting along the tractof the needle.

[0006] Another localization method involves the use of laser light fromthe tip of a optical fiber connected to a laser. A pair of hooks at thetip of the optical fiber secures the tip at the biopsy site; the glowindicates the position of the tip through several centimeters of breasttissue. This procedure suffers from some of the same problems associatedwith the use of barbed or hooked wires. Another preoperativelocalization procedure injects medical-grade powdered carbon suspensionfrom the lesion to the skin surface. This procedure also has certainproblems, including the creation of discontinuities along the carbontrail.

SUMMARY OF THE INVENTION

[0007] The present invention is directed to a target tissue localizationdevice including an elongate placement device having first and secondmembers being longitudinally movable relative to one another. An anchoris secured to the first and second members and is movable from a first,radially contracted configuration to a second, radially expandedconfiguration. The placement device and anchor are sized and configuredfor use in localization of target tissue. According to one aspect of theinvention the anchor is a tubular mesh anchor. According to anotheraspect of the invention the anchor has a sufficiently largecross-sectional area when in the second, radially expanded configurationto substantially eliminate inadvertent dislodgment of the anchor onceradially-expanded.

[0008] A further aspect of the invention relates to a method forlocalizing target tissue including determining the location of thetarget tissue and passing the distal end of an elongate localizationdevice through the patient's skin and to the target tissue to create atissue track between the patient's skin and the target tissue. Thetarget tissue includes a near side toward the patient's skin and a farside opposite the near side. The localization device includes an anchorelement secured to a placement device, the placement device extendingfrom the anchor element along the tissue track and through the patient'sskin. The anchor element is located at the target tissue and expanded toan expanded configuration. According to one aspect of the method theanchor element is located on the far side of the target tissue.According to another aspect of the method, the localization device isselected with an anchor which is palpable at the patient's target tissueso that the target tissue can be relocated at least in part by palpationof the patient to locate the anchor; according to this aspect of theinvention, at least a sample of the relocated target tissue is removed.The elongate localization device can be used as a guide or guide wirefor further diagnostic of therapeutic procedures.

[0009] In preferred embodiment of the invention the anchor is a tubularmesh anchor which can be placed into a disk-like shape when in the fullyexpanded configuration or in a more flattened spherical shape, that isnot as flat as the disk-like shape, which may aid in palpability. Theanchor may also be in other forms such as a Malecot-type of radiallyexpandable anchor. Another anchor embodiment could be deployed from theend of a hollow sheath and include numerous resilient curved projectionswhich extend generally radially outwardly to fully surround the sheath.

[0010] The invention may find particular utility as an aid in theremoval of small, difficult-to-grasp body structures, such as lymphnodes or other tissue that is difficult to grasp. The anchor could bepositioned behind or inside a lymph node targeted for removal; lymphnode removal can be aided by leaving the anchor in its expanded positionso that after the surgeon cuts down to the lymph node, the lymph node,some surrounding tissue and the entire localization device can beremoved for further analysis.

[0011] In some situations the anchor may be left in a partially or fullyradially-expanded condition and used to pull the target tissue from thepatient, typically with the aid of the surgeon opening the tissue track.For example, for tumor removal of the breast, the anchor may be used ina partially or fully expanded condition so that the tumor andsurrounding margins can be removed during lumpectomy. Similar procedurescan be used in regions other than the breast.

[0012] The invention may also include structure which may enhanceultrasound visibility. Invention may include certain treatment, grooves,slits, or other structure to enhance the ultrasonic visibility of theplacement device or the delivery needle, or both. Also, the mesh anchormay provide sufficient reflectivity so that treatment of the placementdevice and delivery needle is not required. Other techniques forenhancing remote visualization, such as radiopaque markers, can also beused.

[0013] The invention is primarily related to mammographic localization,but may find utility with other areas of imaging including ultrasound,thoracoscopy, nuclear medicine, MRI, computed tomography, plain film andany other image guided technology.

[0014] The present invention provides a simple, relatively inexpensive,very stable localization device to locate a lesion or other targettissue, typically within the breast of a patient, for subsequent biopsy,excision, intervention, or other purpose. The localization device iseasy to insert, deploy, reposition if needed, and remains anchored atthe target site substantially better than conventional localizationneedles. Further, the invention aids relocation of the target tissue bybeing configured to permit location by palpation by the surgeon in theoperating suite. This permits the surgeon to proceed using much lessradical techniques, which may be both cosmetically and surgicallyadvantageous.

[0015] Other features and advantages of the invention will appear fromthe following description in which the preferred the embodiments havebeen set forth in detail in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 illustrates a conventional hollow insertion needle and hookwire;

[0017]FIG. 2 illustrates the hook wire of FIG. 1 inserted into theinsertion needle with the barb extending through the opening in theinsertion needle;

[0018]FIG. 3 is an overall view of a localization assembly madeaccording to the invention with the anchor in a radially expanded,deployed condition;

[0019]FIG. 4 is a partial cross-sectional view of the distal portion ofthe localization device of FIG. 2 with the anchor in a radiallycontracted configuration;

[0020]FIG. 5 illustrates the localization device of FIG. 4 with theanchor moved to a radially expanded configuration by the movement of thedistal ends of the outer sleeve member and the inner wire member towardsone another;

[0021]FIG. 5A is a cross-sectional view taken along line 5A-5A of FIG.5;

[0022]FIG. 6 illustrates a further embodiment of the localization deviceof FIG. 4 in which the inner wire member has been replaced by an innershaft member having a pointed distal end to potentially eliminate theneed for the delivery needle of FIG. 3;

[0023]FIG. 7 illustrates the device of FIG. 6 with the anchor in a firstradially expanded condition, the anchor forming a somewhat flattenedspherical shape;

[0024]FIG. 8 illustrates the localization device of FIG. 7 with theanchor in a fully radially expanded configuration in the shape of agenerally flat disk, the anchor illustrated positioned on the far sideof a lesion or other target tissue;

[0025]FIG. 9 illustrates an alternative embodiment of the localizationassembly of FIG. 3 in which the localization device of FIG. 3 has beenreplaced by a localization device having an inner shaft member and anouter shaft member, the outer shaft member having a series oflongitudinally extending slits formed at its distal end;

[0026]FIG. 10 illustrates the localization device of FIG. 9 with theinner shaft member pulled relative to the outer sleeve member causingthe sleeve segments to expand radially to form a Malecot-type anchor;and

[0027]FIG. 11 illustrates a further alternative embodiment of theinvention in which the anchor is in the form of an expandable balloon,the balloon mounted to the distal end of a shaft, the balloon-typeanchor and distal shaft end housed within a delivery needle;

[0028]FIG. 11A illustrates the embodiment of FIG. 11 which theballoon-type anchor is in its radially-contracted condition and ispositioned past the sharpened tips of the delivery needle; and

[0029]FIG. 11B illustrates the shaft and balloon-type anchor of FIG. 11Awith the balloon-type anchor in its radially-expanded, deployedcondition.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

[0030]FIG. 1 illustrates a conventional hollow insertion needle 2 placednext to its associated hook wire 4. Insertion needle 2 has a sharpenedtip 6 and an opening 8 set back away from tip 6. Hook wire 4 includes ashaft 10 and a barb 12 extending off the distal end of the shaft.Insertion needle 2 is relatively stiff or rigid while hook wire 4 isflexible but resilient. FIG. 2 illustrate the localization assembly 14made up of the insertion needle 2 and hook wire 4 of FIG. 1 with thebarb 12 extending from opening 8. The condition of localization assembly14 in FIG. 2 is that which would be after tip 6 of insertion needle 2has been properly placed relative to the target tissue and hook wire 4has been pulled proximally causing barb 12 to extend from opening 8 andpass into the patient's tissue. As discussed above, this reliance on athin barb 12 to ensure that assembly 14 does not move after placement isnot particularly well-founded; breast tissue is generally quite soft andpermits barb 12 to be easily dislodged from its initial position thusproviding the surgeon a false indication of the target tissue location.

[0031]FIG. 3 illustrates a localization assembly 20 made according tothe invention. Assembly 20 includes broadly a hollow delivery needle 22having a sharpened tip 24 at its distal end and a hub 26 at its proximalend. Needle 22 houses a localization device 28, see FIGS. 4, 5 and 5A,the localization device including an outer sleeve member 30 and an innerwire member 32. The distal ends 34, 36 of outer sleeve member 30 andinner wire member 32 are secured to the proximal and distal ends 38, 40of a tubular mesh anchor 42, respectively. The relative positions ofhollow delivery needle 22 and outer sleeve member 30 can be locked inplace by a needle/sleeve locking device 44 while the relative positionsbetween outer sleeve member 30 and inner wire member 32 can be securedby a sleeve/wire locking device 46. Anchor 42 is moved from its radiallycontracted condition of FIG. 4 to its radially expanded condition ofFIGS. 3 and 5 by pulling on inner wire member 32 while maintaining outersleeve member 30 in place, or by pushing on outer sleeve member 30 whilemaintaining inner wire member 32 in place, or by both pulling on innerwire 32 and pushing on outer sleeve 30 as suggested by the arrows inFIG. 5.

[0032] Localization assembly 20 is preferably made from conventionalbio-compatible materials, such as stainless steel for delivery needle22, outer sleeve member 30 and inner wire member 32. Anchor 42 ispreferably made of stainless steel or NiTi or a polymer such as Kynar,polyester, nylon, etc., and may be coated with a material such as PTFEor other lubricious coating, such as hydrophilic or hydrophobic coatingcommonly used in medical devices, to help anchor 42 pass through thepatient's tissue both when in the radially contracted condition of FIG.4 and when moved to the radially expanded condition of FIG. 5. The meshmaterial of mesh anchor 42 preferably has a tight enough weave so thatit provides substantial hindrance to passage of the patient's tissue,typically at a breast tissue, through the anchor when in the radiallyexpanded condition of FIGS. 3 and 5. Tubular mesh anchor 42 may besomewhat porous or it could be substantially impervious to fluid flow.Anchor 42 could be, for example, covered with a flexible elastic film toprovide fluid impermeability in the expanded condition.

[0033] In one embodiment anchor 42 is made of wires, or filaments oryarns having a diameter of 0.13 mm (0.005 inch) and spacing of 0.025 mm(0.001 inch) in its contracted condition of FIG. 4. Mesh anchor 42 ispreferably made from wires or other elements have diameters of about0.025 to 0.38 mm (0.001 to 0.015 inch) and a contracted conditionspacing of about 0.0025 to 0.051 mm (0.0001 to 0.002 inch). The lengthof anchor 42 is a large factor in determining how large anchor 42 iswhen in the radially expanded condition of FIGS. 5 and 5A. That is, atubular anchor 42 having a relatively short length when in the radiallycontracted condition of FIG. 4 will have a smaller diameter D when inthe radially expanded condition of FIGS. 5 and 5A as opposed to ananchor with a longer axial length when in the radially contractedcondition of FIG. 4.

[0034] The cross-sectional area D diameter of anchor 42 in the radiallyexpanded condition 2 of FIGS. 5 and 5A, equal to πD÷4, is preferably atleast four times and more preferably at least eight times thecross-sectional area of anchor 42 in the radially contracted conditionof FIG. 4, equal to πd²÷4. Another way of defining the enhancedstabilization created by anchor 42 is based upon the force it would taketo substantially dislodge the anchor from a deployed position within thepatient's breast. Conventional hooked wire embodiments such as that ofFIGS. 1 and 2, which commonly become substantially dislodged when alongitudinally directed pulling force of only about 0.5 to 2 kg (1 to 4pounds) is exerted on localization assembly 14. Anchor 42, due to itslarge surface area opposing any axially-directed force, requires alongitudinally directed pulling force on outer sleeve 30 and inner wiremember 32 to be substantially more than the force required tosubstantially dislodge a hooked wire localization needle to besubstantially dislodged from breast tissue.

[0035] An alternative embodiment of the localization assembly is shownin FIG. 6 with like reference numerals referring to like elements.Localization device 28A is designed to potentially eliminate the needfor the hollow delivery needle 22 of FIG. 3. Outer sleeve 30A isessentially the same with an inner shaft 32A replacing inner wire 32.The distal end 36A of inner shaft 32A is a sharpened point to aidpiercing the patient's tissue. The tubular mesh anchor 42A is secured atits distal and proximal ends 40A and 38A to distal end 36A of innershaft 32A and distal end 34A of outer sleeve 30A. FIG. 7 illustratesresult of collapsing anchor 42A about half way resulting in a generallyflatten spherical shape or ellipsoid of revolution shape. This shapedoes not create as large a cross-sectional area but may be useful inaiding palpability of anchor 42A. FIG. 8 illustrates the result ofcontinuing to collapse inner mesh anchor 42A by pulling on inner shaftmember 32A; doing so results in anchor 42A being similar in shape toanchor 42 of FIGS. 5 and 5A.

[0036] A further embodiment of the invention is illustrated in FIGS. 9and 10. In FIG. 9, a localization assembly 20B is seen to include adelivery needle 22B housing a localization device 28B. Localizationdevice 28B includes an outer sleeve member 30B and an inner shaft member32B. The distal end 34B of outer shaft member 30B has a member ofaxially-extending slits 48 formed therein to define a plurality,preferably six to ten, sleeve segments 50 therebetween. Pulling innershaft member 32B relative to outer shaft member 30B causes sleevesegments 50 to buckle outwardly to create a Malecot-type anchor 52. Toimprove the effective cross-sectional area of anchor 52 in theradially-expanded condition, sleeve segments 50 could be surrounded byan expandable mesh or a film which would effectively cover or fill theregions between sleeve segments 50 when in the expanded condition ofFIGS. 10 and 10A.

[0037] The invention may be used in a manner similar to conventionallocalization devices. The location of the target tissue 56, see FIG. 8,is determined using, for example, mammography, ultrasound, or otherconventional or unconventional techniques. Using the embodiment of FIGS.6-8 as an example, localization device 28A is passed through skin 58 tocreate a tissue path 60 between target tissue 56 and the skin. Targettissue 56 has a near side 62 towards skin 58 and a far side 64 away fromnear side 62 that is facing anchor 42A in FIG. 8. Once in the expandedcondition of FIG. 8, localization device 28A is very resistant to beingmoved or dislodged so that anchor element 42A remains where positioned,in this example on the far side of target tissue 56. Locking device 46is used to maintain the relative axial positions of outer sleeve member30 and inner shaft member 32A. In example FIG. 8, localization device28A is shown having pierced through target tissue 56. In appropriatecases localization device 28A could be positioned to one side of targettissue 56 with anchor 42A opposite far side 64. Distal end 36A couldalso be positioned opposite near side 62 so that the localization device28A does not pierce target tissue 56 and anchor 42A lies opposite nearside 62 rather than far side 64. The surgeon can relocate target tissue56 using localization 28A in several ways. First, when anchor 42A isconstructed for palpability, the surgeon may determine the location oftarget tissue 56 by palpation by sensing the presence and location ofanchor 42A, anchor 42A being harder than the surrounding tissue. Remotevisualization techniques could also be used to determine the location ofanchor 42A and thus of target tissue 56. Appropriate therapeutic ordiagnostic procedures, such as taking biopsy samples of target tissue 56or completely removing target tissue 56, can then be accomplished. Insome situations localization device 28A will remain in position untilanchor 42A is transformed from its radially-expanded condition of FIG. 8to its radially-contracted condition of FIG. 6, at which time device 28Acan be removed from the patient. At other times anchor 42A will remainin its fully radially deployed condition as localization device 28A isused to help pull target tissue 56 along tissue path 60, which may ormay not occur after surgical intervention.

[0038] A further embodiment of the invention is shown in FIGS. 11-11B.This emodiment uses a balloon-type anchor 70 at the distal end of ahollow delivery shaft 72. Anchor 70 is delivered to a target site whilehoused within a hollow delivery needle 22 as shown in FIG. 11. Once atthe proper location, anchor 70 is exposed, as shown in FIG. 11A, bypushing on shaft 72, pulling on needle 22, or both. FIG. 11B showsballoon-type anchor 70 in its radially-expanded, deployed condition, aflattened spherical shape in this embodiment. Balloon anchor 70 may bemade of elastic or inelastic material and can be made to assume avariety of shapes when in the expanded condition. Such shapes includethe disk-like shapes FIGS. 3, 5, 5A, the flattened spherical shapedFIGS. 7 and 11B, star-shaped with radially extending fingers (not shown)or other shapes suitable for the surrounding tissue in which it isdeployed and the circumstances of its use.

[0039] Modification and variation can be made to the disclosedembodiments without departing from the subject of the invention asdefined in the following claims.

[0040] Any and all patents, patent applications and printed publicationsreferred to above are incorporated by reference.

What is claimed is:
 1. A target tissue localization device, forlocalizing target tissue within a soft tissue region of a patient,comprising: a first member having a distal portion; a second memberassociated with the first member and being longitudinally movablerelative thereto; an anchor having first and second portions secured tothe first and second members, respectively; said anchor movable from afirst, radially contracted configuration to a second, radially expandedconfiguration; said anchor having first and second cross-sectionalareas, lying in relatively radially-oriented planes, when in the firstand second configurations, said second area being at least four timessaid first area; and said first and second members and said anchor beingsized and configured for use in localization of target tissue.
 2. Thedevice according to claim 1 wherein the first member is a tubular memberand the second member is slidably housed within the first member.
 3. Thedevice according to claim 2 wherein the second member comprises aflexible wire and the first member comprises a stiff tube.
 4. The deviceaccording to claim 2 wherein the first and second members are stiffmembers.
 5. The device according to claim 1 wherein the first and secondportions of the anchor are proximal and distal portions of the anchor.6. The device according to claim 5 wherein the second member has apointed distal end.
 7. The device according to claim 5 wherein the firstand second members have distal ends and the first and second portions ofthe anchor are secured to the distal ends of the first and secondmembers, respectively.
 8. The device according to claim 1 wherein thefirst and second members have distal ends and the first and secondportions of the anchor are secured to the distal ends of the first andsecond members, respectively.
 9. The device according to claim 1 whereinthe anchor is a soft-breast-tissue-penetrating tubular mesh anchor. 10.The device according to claim 9 wherein the tubular mesh anchor has acircular cross-sectional shape.
 11. The device according to claim 10wherein the tubular mesh anchor has a circumferentially continuous, atleast substantially fluid-impermeable surface.
 12. The device accordingto claim 9 wherein at least a portion of the tubular mesh anchor is adisk-shaped portion having a circumferentially continuous, at leastsubstantially fluid-impermeable surface.
 13. A target tissuelocalization device, for localizing target tissue within a soft tissueregion of a patient, comprising: anchor means, movable from a first,radially contracted configuration to a second, radially expandedconfiguration, for localizing target tissue with said anchor havingfirst and second cross-sectional areas, lying in relativelyradially-oriented planes, when in the first and second configurations,said second area being at least four times said first area; andplacement means for moving the anchor means from the first configurationto the second configuration for the localization of target tissue. 14.The device according to claim 13 wherein the anchor means comprises asoft-breast-tissue-penetrating tubular mesh anchor.
 15. The deviceaccording to claim 14 wherein the tubular mesh anchor has a circularcross-sectional shape.
 16. The device according to claim 15 wherein thetubular mesh anchor has a circumferentially continuous, at leastsubstantially fluid-impermeable surface.
 17. The device according toclaim 14 wherein at least a portion of the tubular mesh anchor is adisk-shaped portion having a circumferentially continuous, at leastsubstantially fluid-impermeable surface.
 18. A target tissuelocalization device, for localizing target tissue within a soft tissueregion of a patient, comprising: soft-tissue-penetrating tubular meshanchor means, movable from a first, radially contracted configuration toa second, radially expanded configuration, for localizing target tissue;and placement means for moving the anchor means from the firstconfiguration to the second configuration for the localization of targettissue.
 19. The device according to claim 18 wherein the anchor is asoft-breast-tissue-penetrating tubular mesh anchor means.
 20. The deviceaccording to claim 18 wherein the tubular mesh anchor means has acircular cross-sectional shape.
 21. The device according to claim 20wherein the tubular mesh anchor means has a circumferentiallycontinuous, at least substantially fluid-impermeable surface.
 22. Thedevice according to claim 18 wherein at least a portion of the tubularmesh anchor means is a disk-shaped portion having a circumferentiallycontinuous, at least substantially fluid-impermeable surface.